Recently, portable telephones and terminal devices, etc. of wireless communication, etc. are required to be further integrated and downsized, and to lower costs.
For this, a semiconductor device having a core unit, an input/output circuit and a high withstand voltage circuit mounted on one and the same semiconductor substrate is noted.
Transistors of the core unit and the input/output circuit unit can be formed by a general CMOS process.
On the other hand, it is preferable that the transistors used in the high withstand voltage circuit ensures high withstand voltage.
Related references are as follows:
Japanese Laid-open Patent Publication No. 2007-49039;
Japanese Laid-open Patent Publication No. Hei 7-161987; and
Japanese Laid-open Patent Publication No. 2011-199153.